The invention is related to vinyl ether ester oligomers useful for coatings and related applications. More particularly, it relates to new methods of preparing such oligomers which provide a range of useful molecular weight materials.
Vinyl ether ester oligomers are disclosed in a group of U.S. Pat. Nos. assigned to Allied-Signal Inc., namely U.S. Pat. Nos. 4,749,807, 4,775,732, and 4,845,265. These patents disclose methods for making the vinyl ether ester oligomers which are not considered commercially useful in preparing oligomers. Where acid chlorides are used, the oligomer contains HCl which must be removed. Where esters are used, the vinyl ethers may be converted in substantial amounts to compounds having an acetal moiety, preventing higher molecular weight oligomers from being formed and potentially interfering with the formation of polymers in subsequent processing. Consequently, new methods for producing vinyl ether ester oligomers have been sought by the present inventors and their improved methods will be disclosed below.